1. Field of the Invention
The present invention relates in general to the field of electrical extension cords and in particular to devices for maintaining an interconnection between electrical extension cord plugs. Still more particularly the present invention relates to a device for preventing the accidental disconnection of electrical extension cord plugs.
2. Description of the Prior Art
The interconnection of flexible electrical extension cords to transmit electrical power from a source, such as a household electrical outlet, to an electrical device is very common. In the household environment several extension cords may be interconnected to provide power to a device, such as an electrical lawn mower or electric hedge trimmer for use at a substantial distance from a power outlet. Interconnected extension cords may also be utilized in commercial applications, particularly by construction workers operating hand tools or other devices remotely from a power outlet.
A typical electrical extension cord includes a male and female plug which are interconnected by a flexible extension cord cable. In many extension cords the female plug of one cord extension is connected to the male plug of a second cord by receiving a spade type conductor from the male plug and urging internal conductors into contact therewith. On many occasions, the application of tension to a cable consisting of a connected pair of electrical extension cords will induce separation or disconnection of conductors in the plugs and thereby prevent the transmission of electrical power. This quite naturally results in an inconvenience and expense caused by the necessity to manual reconnect the plugs.
One solution to this problem has been the use of "twist-lock" connectors. These find acceptance in heavy duty industrial and theatrical settings. "Twist-lock" connectors employ special prongs and receptacles which are not compatible with normal home or light industrial wall plugs or with the connections on normally utilized household extension cords. Therefore, this solution, while effective in an industrial setting, will not work in common household applications.
One solution proposed to this problem has been to equip a connection with an appliance or accessory which holds two ends of the connection in an interconnected engagement. U.S. Pat. No. 3,383,639, issued to Anderson et al, discloses a clamp device which fits around two ends of a connection and holds the two plugs in connection. Although this device has the advantage of being easy to utilize, it requires complete removal when the plugs are separated.
U.S. Pat. No. 3,014,194, issued to Berglund, discloses a cable connector protector which is a single body which clamps around a connected set of plugs.
U.S. Pat. No. 3,030,601, issued to Krebs, discloses a very simple device which is a one piece jacket formed of a rubber like material which slips around two connected cables.
U.S. Pat. No. 4,169,643, issued to Gallagher, discloses a mating clip wherein the connected ends of the receptacle and plug are latched together within a closeable container.
Similarly, U.S. Pat. No. 4,643,505, issued to House et al, discloses a device in which latched-together electrical connector plugs are clamped within a housing to secure the connection.
U.S. Pat. No. 4,690,476, issued to Morgenrath, discloses an electrical connector securing system wherein each end of the coupling is equipped with a housing and two housing are held together utilizing straps.
U.S. Pat. No. 4,784,612, issued to Ryan, discloses a pair of housings, one on each half of an electrical connector, which thread together to secure the connector halves in a connected state.
Finally, U.S. Pat. No. 4,940,424, discloses a device including two members, one surrounding a male plug and a second surrounding a female plug. These members are cylindrical and engage one another with protuberances on one member sliding and latching in grooves within the other member.
While the devices disclosed in the above-referenced patents have been effective in certain circumstances, there remains a need for a light weight, inexpensive device which be utilized to maintain the connection between extension cords. In particular, it would be most desirable to provide a device performing this function which is adaptable for use with a wide cross section of the multitude of extension cord designs which are currently available.